草酸铁光催化协同络合铁脱硝剂再生过程

Regeneration process of complexing iron denitration agent synergized with iron oxalate photocatalysis

基于Fe(C_2O_4)_3的光化学性质,研究了Fe(C_2O_4)_3光催化协同络合铁脱硝剂再生的实验过程。实验考察了在50℃和Fe(Ⅱ)EDTA浓度为0.01 mol·L^(-1)以及NO进口浓度为530 mg·m-3的模拟烟气脱硝系统中,光催化再生模式、初始p H、Fe(C_2O_4)_3浓度及组成、氧气浓度对再生过程的影响。结果表明:Fe(C_2O_4)_3分开加入和分步光照是适合于本体系的反应方式;草酸钠与硫酸亚铁的最佳浓度比为3,浓度分别为0.06和0.02 mol·L^(-1),吸收液初始p H为5.3,有氧参与条件下,实现了络合剂有效再生,再生吸收液脱硝率最高可恢复到60%左右;氧在再生过程中表现出正协同效应。通过牺牲光敏性的草酸铁配体再生脱硝络合剂,建立了一种温和的光助低温湿式氨法同步脱硫脱硝过程。

This paper researched into regeneration of denification agent aided by photocatalysis of Fe（C2O4）3 based on the photochemical properties of Fe（C2O4）3. The investigated factors were the mode of illumination, the addition mode of Fe（C2O4）3, initial p H, Fe（C2O4）3 concentration, the ratio of Na2C2O4 to FeSO4, and oxygen concentration at 50？C of system temperature and 0.01 mol·L^-1 of Fe（Ⅱ）EDTA concentration and 530 mg·m^-3 of the inlet NO concentration. Experimental results indicated that Na2C2O4 and Fe SO4 added into NO-riched solution after NO absorption finishing was the adequate mode for this system. The optimum ratio value of Na2C2O4 to Fe SO4 was 3 with their concentrations of 0.06 and 0.02 mol·L^-1, respectively. Meanwhile, when the initial p H of absorption solution was about 5.3, and oxygen participated in regeneration reaction, the complexing agent got the highest regenerated denification efficiency of 60%. Oxygen played a positive effect on the regeneration process. According to this research, a process of mild photocatalytic-aided wet ammonia desulfurization and denification simultaneously could be established at the expense of Fe（C2O4）3.